Remember the worksheet for which you rolled
dice?The point of the worksheet was to
examine the sampling distribution of the sample mean.That’s why I had you generate several samples
(of dice rolls) and calculate the sample mean for each sample – so we could see
how these sample means vary.Now I want
to do the same thing for a different statistic: the sample proportion.So I want you to generate several samples (of
coin spins this time), and calculate the sample proportion (of heads) in each
sample – so we can see how these sample proportions vary.Get ready for more tedium!

First, I want to make sure you understand the
spinning process.You must give the
penny lots of rotational momentum, and it must come to rest without hitting
anything.The former requires that you
don’t just give the coin a little twist with your wrist, but that you hold the
penny on edge with one finger and flick it with your other finger – as if
place-kicking a football, sort of.The
latter requires a large, flat, hard surface.If the penny hits anything before coming to rest, disregard that
attempt.

Believe it or not, pennies spun in this fashion are
not equally likely to land heads up and tails up.I’ll explain why after we collect the
data.Please use a penny from the
1960’s; 1961 and 1962 are ideal to bring out this effect.Record the year of the penny that you use:
______

For now, I’d like you to generate three samples of
10 spins each, and three samples of 20 spins each.Then calculate the proportion of heads in
each of those samples.(The sample
proportions should be multiples of 0.1 in the samples of 10, and multiples of
0.05 in the samples of 20.)

spin:

1

2

3

4

5

6

7

8

9

10

prop. of H’s

sample 1

sample 2

sample 3

spin:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

prop.H’s

sample1

sample2

sample3

Last but not least, I want you to draw three random
samples of 20 students from the 1995 Witt New Student population, listed on the
back of this sheet, and record the proportion of students from Ohio in each of
your three samples.(Be sure to use
three-digit numbers in your randomization.)